Image Forming Apparatus Toner Amount Dynamic Range Correction
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Solution Overview
Problem
Conventional methods for limiting toner or ink consumption in image forming apparatuses often result in deteriorated gradation properties of dark areas and loss of image information, as they narrow the color reproduction range by reducing image signal levels uniformly.
Innovation Solution
An image forming apparatus that corrects pixel values based on the distribution of recording agent amounts, using a toner amount dynamic range correction process to compress density ranges and prevent image quality degradation, by calculating and adjusting toner amounts for each pixel and its peripheral area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If image signal levels are reduced by a certain fixed ratio to limit toner or ink consumption, then the consumption amount of recording agent is reduced, but the gradation properties of dark areas are deteriorated and image information is lost
Solution Approach 1:
The patent applies local quality by calculating the standard deviation of toner amounts for each pixel and its peripheral area, then selectively compressing only those pixels where the standard deviation exceeds a threshold. This localized approach ensures that toner consumption is reduced in areas where it is excessive, while preserving image information in areas where the toner distribution is already uniform and appropriate.
Solution Approach 2:
The patent changes the parameter of toner amount compression dynamically based on the calculated standard deviation. Instead of applying a fixed compression ratio to all pixels, the system adjusts the compression level for each pixel based on its local toner distribution characteristics, thereby reducing overall toner consumption while maintaining image quality in regions where compression would be harmful.
2Loss of substance
If image signal levels are reduced uniformly to limit recording agent consumption, then the overall toner or ink usage is reduced, but the color reproduction range is narrowed and image quality is degraded
Solution Approach 1:
The patent implements local quality by performing toner amount compression selectively on a pixel-by-pixel basis. Each pixel is evaluated based on the standard deviation of toner amounts in its local area, and compression is applied only where necessary. This localized processing maintains image quality in regions where the toner distribution is already optimal, while reducing consumption in regions where excess toner is present.
Solution Approach 2:
The patent applies dynamics by making the toner compression process adaptive rather than static. The compression ratio for each pixel is determined dynamically based on the calculated standard deviation of toner amounts in its peripheral area. This dynamic approach allows the system to adjust compression levels in real-time based on local image characteristics, thereby reducing overall recording agent consumption while preserving image quality.
Data Source
AI summary
When a recording agent amount limiting process is carried out, a color reproduction range is narrowed, and therefore gradation properties of dark areas are deteriorated and information originally held by an image is sometimes undesirably lost. By obtaining (401) a colorant amount for each target pixel of input color image data, calculating (402) a colorant amount of a peripheral area of the target pixel, and correcting (400) a density range of the input color image data based on the colorant amount of the target pixel and the colorant amount of the peripheral area of the target pixel, amounts of recording agent are limited and reductions in image quality are prevented.